Ratio Rockers and uncut pushrods

[woz]

Need to get opinions on this please

Done the 500 mile run in and started to make the adjustments to valve clearances when i found this.

Rather than just put a new one in i have tried to find why it happened. I now have the engine out and back on the bench, removed the head and there has been not contact so took the rocker assy apart and found scorch marks. Not sure if you can see them very well in the picture but the marks were on both inlet valves.

After hours of head scratching i realise that the push rods are different at each end. the hole diameters are the same but one end has a chamfer. Have a look at the picture below you will see how much smaller the middle one looks.

So do you think it is possible that as the end rotates in the rocker arm that if it doesn't have the chamfer it shuts off or restricts oil flow?

The rockers are 1:25 and the pushrods are uncut bugpack

I know that in both positions that i found the scorch marks that the push rod ends had no chamfer. I have also purchased a new set and all of the ends have a chamfer.

Cheers for any help Woz

 

[K@rlos]

Is the valve geometry all correct?

 

[six]

whats the spec of the engine, cam rocker ratio spring types etc

 

[woz]

Is the valve geometry all correct?

whats the spec of the engine, cam rocker ratio spring types etc

Thanks for your help guys

The engine is a 1641 twinport. Rebuilt it about two years ago and at the time had it align bored. The cam is engle 100 which came with new springs. Fitted new b+p and new heads. The rockers are 1:25 with swivel feet and cut to length push rods.

I set the geometry at the time but it was the first time i had done it. So in answer to the question yes i think its right but i will go back and re-check. Also i have read that the adjustable push rod (used to set the geometry) has a different top to the cut to length ones and doesn't locate in the rocker arm the same way, not sure if there is any truth in this as there is a lot of info on the internet.

I have only just reached the 500 mile mark with the engine

Woz

 

[six]

Stock valve springs?

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[woz]

I bought the Engle 100 cam and it came with springs. on their website it says that it is ok for ratio rockers 1:25 are you thinking i need different springs?

 

[six]

No think that it's too much for the rods. HD Ali or steel rods also reset your valve train first. Use a cut up stock rod to make an adjustable one. Then get some cut to length

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[K@rlos]

Can't beat chromoly push rods IMO, they are noiser than Ali rods but ALOT stronger.

 

[privatejobs]

tis true its wot i got sounds like a noisey sewing machine :lol:

 

[woz]

No think that it's too much for the rods. HD Ali or steel rods also reset your valve train first. Use a cut up stock rod to make an adjustable one. Then get some cut to length

Sent from my Nexus 4 using Tapatalk

Can't beat chromoly push rods IMO, they are noiser than Ali rods but ALOT stronger.

tis true its wot i got sounds like a noisey sewing machine :lol:

Thanks for your help guys - Do you think the Alli ones are no good full stop or do you think they would be ok for the engine i'm running? dont forget its 1641 with engle100 cam and ratio rockers. So very mild mods.

If one of the ends wasnt pressed home fully when i cut them maybe it pushed in when i first started it therefore changing the valve clearance and giving loads of lash and pushing the tip into the rod.

Woz

 

[six]

e100 with ratio rockers and HD springs is quiet alot of extra strain on the valvetrain.

get your cut to lengths done on a lathe and pushed in sq. mantons are ace make sure u get the angles too

good luck